/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.harmony.security.x509;

import java.io.IOException;

import javax.security.auth.x500.X500Principal;

import org.apache.harmony.security.asn1.ASN1Sequence;
import org.apache.harmony.security.asn1.ASN1Type;
import org.apache.harmony.security.asn1.BerInputStream;
import org.apache.harmony.security.x501.Name;

/**
 * CRL Entry's Certificate Issuer Extension (OID = 2.5.29.29). It is a CRL entry
 * extension and contains the GeneralNames describing the issuer of revoked
 * certificate. Its ASN.1 notation is as follows:
 * 
 * <pre>
 *   id-ce-certificateIssuer   OBJECT IDENTIFIER ::= { id-ce 29 }
 * 
 *   certificateIssuer ::=     GeneralNames
 * </pre>
 * 
 * (as specified in RFC 3280) In java implementation it is presumed that
 * GeneralNames consist of one element and its type is directoryName.
 */
public class CertificateIssuer extends ExtensionValue {

	// certificate issuer value
	private X500Principal issuer;

	/**
	 * ASN.1 Encoder/Decoder.
	 */
	public static final ASN1Type ASN1 = new ASN1Sequence(
			new ASN1Type[] { GeneralName.ASN1 }) {
		@Override
		public Object getDecodedObject(BerInputStream in) {
			return ((Name) ((GeneralName) ((Object[]) in.content)[0]).getName())
					.getX500Principal();
		}

		@Override
		protected void getValues(Object object, Object[] values) {
			values[0] = object;
		}
	};

	/**
	 * Creates an object on the base of its encoded form.
	 */
	public CertificateIssuer(byte[] encoding) {
		super(encoding);
	}

	/**
	 * Creates an object on the base of GeneralName structure.
	 */
	public CertificateIssuer(GeneralName issuer) {
		super(ASN1.encode(issuer));
	}

	/**
	 * Places the string representation of extension value into the StringBuffer
	 * object.
	 */
	@Override
	public void dumpValue(StringBuffer buffer, String prefix) {
		buffer.append(prefix).append("Certificate Issuer: "); //$NON-NLS-1$
		if (issuer == null) {
			try {
				issuer = getIssuer();
			} catch (final IOException e) {
				// incorrect extension value encoding
				buffer.append("Unparseable (incorrect!) extension value:\n"); //$NON-NLS-1$
				super.dumpValue(buffer);
			}
		}
		buffer.append(issuer).append('\n');
	}

	/**
	 * Returns the issuer.
	 */
	public X500Principal getIssuer() throws IOException {
		if (issuer == null) {
			issuer = (X500Principal) ASN1.decode(getEncoded());
		}
		return issuer;
	}
}
